NAIROBI, Kenya — For two terrifying hours, the woman crouched
inside her shop, watching as a gang attacked five men in the
street, pulled down their trousers and sliced their genitals with
rusty machetes.

‘‘The men were screaming and saying, ’Please don’t kill me, don’t
cut me,’’’ the 35-year-old vendor told The Associated Press,
asking to be identified only by one initial, K., because she
feared reprisals by the gang.

In the violence that has followed Kenya’s disputed presidential
election, a notorious gang has been mutilating the genitals of
both men and women in the name of circumcision — inflicting a
brutal punishment on members of a rival tribe that does not
traditionally circumcise.

The attacks do not appear to be widespread, but they drive home
how a fight touched off by opposition allegations that Kenya’s
president stole the election has exploded into a broader conflict
fueled by ethnic resentments in what had been one of Africa’s most
stable nations.

Many of the mutilation victims belong to the Luo tribe of
opposition presidential candidate Raila Odinga, say witnesses and
even a recruiter for the gang itself.

The gang, called the Mungiki, draws mostly from President Mwai
Kibaki’s Kikuyu tribe, which has long dominated politics and
business in this East African country.

Mungiki, which means ‘‘multitude’’ in Kikuyu, originally promoted
traditional Kikuyu practices, including female genital mutilation.
But in recent years it has become involved in extortion and murder
and it also provides hired muscle for politicians.

The recruiter called forced ‘‘circumcisions’’ simple revenge on
Luos for attacks on Kikuyus since the Dec. 27 election. More than
600 people have been reported killed in the upheaval.

‘‘They must pay for the destruction and the deaths,’’ the female
recruiter said, speaking on condition of anonymity because the
gang has been outlawed since 2002, after its members beheaded 21
people in a turf war with a rival gang.

Circumcision is a rite of passage for male members of the Kikuyu
and most other Kenyan tribes, but the Luos do not practice it.

Millie Odhiambo-Mabona, a lawyer with a children’s rights group
who reported hearing of numerous such attacks, said mutilation is
a ‘‘weapon of war’’ for groups that practice traditional
circumcision.

‘‘Because for the communities that don’t practice circumcision, if
you forcefully circumcise them, then it’s meant to be degrading,’’
she said from Nairobi in a telephone interview with the AP in New
York.

The number of mutilations appears to be relatively small, measured
against the violence that has wracked Kenya.

K., interviewed in the Nairobi slum of Kibera, reported seeing
five men harmed in this way, including at least two whose penises
were cut off and thrown into a fire. She said she believed those
men died because she saw the attackers throw the bodies behind
some kiosks.

The Mungiki recruiter confirmed three other ‘‘forced circumcisions.’’

A surgeon at Kenyatta National Hospital, the main government
hospital in the capital, said he had operated on two men with
injuries to their penises, at least one of whom was a Luo.

‘‘There were cuts around the foreskin, probably an attempt at
circumcision,’’ the doctor said, speaking on condition of
anonymity.

A mortuary assistant in Nairobi said out of 78 bodies brought to
his facility since the fighting started, two adult males appeared
to have been crudely circumcised before being hacked to death. The
assistant insisted on speaking anonymously out of fear of
reprisals.

‘‘We have received some reports of what’s happening to
predominantly Luo men who are not believed to be circumcised,’’
said Muthoni Wanyeki of the Kenyan Human Rights Commission.
‘‘These attacks are happening in areas that Mungiki is active.’’

K., the vendor, said she recognized the attackers outside her shop
as Mungiki. She said that over a two hour period, she watched the
gang waylay five men; each attack took about five minutes.

‘‘My husband also was hiding at the shop with me,’’ she said. ‘‘My
husband was afraid they were going to attack him next so we stayed
quiet, quiet.’’

Since witnessing the mutilations, K. has abandoned her business
selling vegetables and chickens in a predominantly Kikuyu area of
Kibera.

‘‘I will never go back there,’’ she said. ‘‘I hear it’s still
going on.’’

John Holmes, the United Nations undersecretary-general for
humanitarian affairs, said he had received reports of genital
mutilation.

He said the United Nations calls on ‘‘all leaders to stop this
kind of violence, to nip this kind of ethnic fighting and singling
out people for attacks on the basis of ethnicity in the bud before
it becomes any worse.’’

Dr. Samwel Oyugi, a Kenyan who practices geriatric and internal
medicine in New York but has been visiting his homeland during and
after the election, said several people had told him about genital
mutilations.

‘‘What they say they saw were some of their relatives that were
forcefully circumcised, and some that were killed,’’ Oyugi said in
a telephone interview with AP in New York. ‘‘Basically, you’re
held down by a group of people from the Kikuyu tribe, and they
basically cut your foreskin, without any regards to how much pain
they cause.’’

Edward Omolo, a Kenyan who teaches biology at Central
Pennsylvania’s Community College, said he had heard of about 20
mutilation killings, including his 45-year-old Luo uncle who bled
to death after suffering forced ‘‘circumcision’’ in a Nairobi slum
around Dec. 30.

‘‘He was killed, circumcised to death,’’ said Omolo, who spoke
with the AP during two interviews, one in person outside U.N.
headquarters in New York, the other by phone from his office.
Omolo, who also said a niece and her 7-month-old daughter had been
hacked to death by matchetes in another attack, blames Kibaki for
the bloodshed. He drove last week from Harrisburg to New York to
join about 50 protesters demanding a new government for Kenya.

‘‘The only way is to get a legitimate government, and let that
government sort out the problems,’’ he said.